SHINDO3

NDL

National Diet Library

Personal data4,373records

POSSIBLE LEAKFull name / Usage historyUnauthorized access · Contained

Open in the live monitor ▶
Disclosed
Nov 11, 2025
Leak
Leak possible
Type
Unauthorized access
Status
Contained
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityFull name
Account dataUser ID
Transactions & activityMaterials copied and purpose of use

How many

  • Copy service application records 4,373 records
  • Library visitors 4,360 people

Who is affected

  • Library visitors

Cause

Business equipment of Solution One, a subcontractor of prime contractor IIJ, was compromised by an unknown party, and the development environment was accessed through the work network

Timeline

  1. Intrusion began
  2. Intrusion stopped
  3. First disclosure
  4. Scope of impact announced

Response

  • Blocked the entry point
  • Forensic investigation

What you should do

  1. Check the company's notice to see if you're affected

Lessons for companies

  1. Put security requirements, audit rights and reporting deadlines in vendor contracts
  2. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  3. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources